This application claims priority from Japanese patent application of Tajima et al, filed Dec. 28, 2000, No. 2000-403092, the complete disclosure of which is hereby incorporated into the present application by this reference.
1. Field of the Invention
The present invention relates to a passenger""s seat airbag device to be arranged in an instrument panel (as will be shortly referred to as the xe2x80x9cin-panexe2x80x9d) in front of a passenger""s seat.
2. Description of the Related Art
In the passenger""s seat airbag device of the prior art, the airbag is constructed to include an opening side wall portion having a gas inlet port for introducing an inflating gas, and a passenger""s side wall portion for confronting the passenger when the airbag is extended/inflated. This airbag is folded up and housed in a case which is arranged in the in-pane in front of the passenger""s seat. When the inflating gas is introduced, moreover, the airbag is extended/inflated to protrude from the opening in the upper face of the in-pane backward of the vehicle (as referred to Unexamined Published Japanese Patent Application No. 11-278192).
The airbag of this kind is desired to protrude, when extended/inflated, toward the passenger in a widely open state and at a suppressed moving velocity so that it may not apply a partial pushing force to the passenger.
In the airbag of the prior art, therefore, the passenger""s side wall portion is horizontally and vertically folded in such predetermined manners that it is flatly overlapped close to the opening side wall portion side. Moreover, the airbag is guided, when extended/inflated, to protrude along the windshield toward the passenger. At this time, the passenger""s side wall portion is arranged with a wide opening and generally in the vertical direction.
However, the airbag has been troubled by the following problems, if it is provided, when completely extended/inflated, with the passenger""s side wall portion and the peripheral wall portion. The passenger""s side wall portion is arranged generally in the vertical direction on the passenger""s side when the airbag is completely extended/inflated. The peripheral wall portion is narrowed generally into a conical shape forward of the vehicle from the outer peripheral edge of the passenger""s side wall portion. A gas inlet port is arranged as an open face generally in the horizontal direction in front of the lower side of the peripheral wall portion when the extension/inflation is completed. Moreover, the airbag is mounted at its gas inlet port peripheral edge in the case.
In this airbag, the peripheral edge of the gas inlet port of the peripheral wall portion is arranged generally in the horizontal direction when the airbag is completely inflated by itself. Moreover, the passenger""s side wall portion is arranged generally in the vertical direction. In other words, the peripheral edge of the gas inlet port is generally normal to the passenger""s sidewall portion which is arranged generally in the vertical direction. Even if the horizontal or vertical folding is done by overlapping the passenger""s side wall portion so flatly on the peripheral wall portion as comes closer to the gas inlet port, therefore, there arises a problem that the passenger""s side wall portion is hard to arrange quickly generally in the vertical position when the airbag is extended/inflated.
The present invention has been conceived to solve the above-specified problems and has an object to provide a passenger""s seat airbag device which can arrange the passenger""s side wall portion quickly generally in the vertical direction with respect to the gas inlet port peripheral edge when the airbag is extended/inflated.
The object of the present invention can be achieved by a passenger""s seat airbag device having the following construction.
Here, the longitudinal and transverse directions are taken herein to correspond to the longitudinal and transverse direction of a vehicle running straight, with respect to the state in which the passenger""s seat airbag device is mounted on the vehicle. Moreover, the upper edge and the lower edge of the passenger""s side wall portion in the airbag are taken with respect to the state in which the airbag is completely extended/inflated.
According to an aspect of the present invention, there is provided a passenger""s seat airbag device comprising: an airbag folded up and housed in a case for being extended/inflated and protruded backward of a vehicle while pushing and opening a door arranged in an instrument panel, by introducing an inflating gas thereinto from a gas inlet port.
The airbag includes, as a shape when completely extended/inflated:
a passenger""s side wall portion arranged on the passenger""s side and generally in a vertical direction; and
a peripheral wall portion converging generally into a conical shape from the outer peripheral edge of the passenger""s side wall portion forward of the vehicle.
The gas inlet port is arranged as an open face on the front side on the lower side of the peripheral wall portion when the airbag is completely extended/inflated.
The gas inlet port is mounted at its peripheral edge on the case.
The airbag is so shaped, when preliminarily folded, that a portion near the upper edge of the passenger""s sidewall portion is arranged at a position to confront the gas inlet port to lay the passenger""s side wall portion flatly on the lower side of the peripheral wall portion.
In the passenger""s seat airbag device of the aforementioned construction, the airbag introduces, when extended/inflated, the inflating gas thereinto from the gas inlet port so that it is extended/inflated while eliminating the horizontal and vertical creases. At the position to confront the gas inlet port at the preliminarily folding time of the airbag, there is arranged the portion which is near the upper edge of the passenger""s side wall portion. Therefore, the portion near the upper edge of the passenger""s side wall portion to confront the gas inlet port is forcibly pushed up prior to the remaining portions such as the portion of the lower edge side of the passenger""s side wall portion by the pushing force of the inflating gas just introduced. As a result, the passenger""s side wall portion can be easily arranged generally in the vertical direction.
If the portion near the upper edge of the passenger""s sidewall portion is forcibly pushed up, moreover, the horizontal and vertical creases can be quickly eliminated. Therefore, the passenger""s side wall portion can be widely extended.
In the passenger""s seat airbag device according to the present invention, therefore, the passenger""s sidewall portion to take the position generally perpendicular to the gas inlet port peripheral edge can be quickly arranged generally in the vertical direction when the airbag is extended/inflated. Moreover, the airbag can be extended in the widely open state so that no partial pushing force may be applied to the passenger""s side.
In the aforementioned passenger""s seat airbag device, it is preferred that when the airbag is preliminarily folded, the peripheral wall portion is folded up to extend substantially all the area of the passenger""s side wall portion flatly.
With this construction of the preliminarily folded shape of the airbag, substantially all the area of the passenger""s side wall portion may be flatly extended and folded up on the peripheral wall portion side when the airbag is preliminarily folded. Therefore, it is possible to do the preliminarily folding work of the airbag conveniently. Moreover, substantially all the area of the passenger""s side wall portion is flatly extended at the preliminarily folding time so that the airbag can move more easily toward the passenger""s side while being extended widely vertically and transversely than the case in which the passenger""s side wall portion is folded up. As a result, the moving velocity of the passenger""s side wall portion to the passenger""s side can be further suppressed.
In the passenger""s seat airbag device, moreover, in the preliminarily folded shape of the airbag, it is preferable that the portion of the peripheral wall portion on the upper side of the gas inlet port is folded up within the range on the front side from the vicinity of the rear edge of the gas inlet port.
In the case of this construction, the portion of the peripheral wall portion over the gas inlet port may be folded up on the front side of the front or rear edge of the gas inlet port or folded up to clog the gas inlet port. With this construction, however, there can be obtained the following actions and effects.
Specifically, the portion of the peripheral wall portion over the gas inlet port is folded up within the range from the rear edge to the front side of the gas inlet port but not to extend largely backward from the gas inlet port. When the inflating gas flows in from the gas inlet port, moreover, the portion of the passenger""s side wall portion near the upper edge is pushed up through the portion of the peripheral wall portion on the upper side of the gas inlet port. At this time, the portion itself of the peripheral wall portion on the upper side of the gas inlet port is also pushed up. Moreover, the portion of the peripheral wall portion on the upper side of the gas inlet port is unfolded to leave the gas inlet port as it is pushed up. Therefore, the portion near the upper edge of the passenger""s side wall portion comes into a state to confront the gas inlet port directly. As a result, the passenger""s side wall can be easily arranged generally in the vertical direction.
With the construction described above, therefore, the action to arrange the passenger""s side wall portion quickly generally in the vertical direction is not obstructed even if the portion of the peripheral wall portion over the gas inlet port is interposed between the gas inlet port and the portion near the upper edge of the passenger""s side wall portion. Of course, the passenger""s side wall portion can be more quickly arranged generally in the vertical direction if the portion of the peripheral wall portion on the upper side of the gas inlet port is folded up on the front side of the rear edge of the gas inlet port. If the portion of the peripheral wall portion on the upper side of the gas inlet port is folded up on the front side of the front edge of the gas inlet port, moreover, the passenger""s side wall portion can be more quickly arranged generally in the vertical direction.
In the aforementioned passenger""s seat airbag device, moreover, in the preliminarily folded shape of the airbag, it is preferred:
that the portions of the peripheral wall portion on the left and right sides of the gas inlet port are so folded to form valley creases in the longitudinal direction that the intermediate portion of the flatly extended passenger""s side wall portion to the left and right edges is brought close to the gas inlet port and arranged at the passenger""s side wall portion side at the peripheral edge of the gas inlet port, and
that the portion of the peripheral wall portion near the joint to the upper edge of the passenger""s side wall portion is folded to form valley creases in the transverse direction.
With the aforementioned construction of the preliminarily folded shape of the airbag, the airbag is folded up at its peripheral wall portion symmetrically with respect to the gas inlet port, so that it can be easily preliminarily folded.
In the preliminarily folded shape of the airbag in the aforementioned construction, the peripheral wall portion can be preliminarily folded by gripping and pulling the two predetermined portions of the airbag away from each other. One gripped portion is located at a substantially intermediate portion in the peripheral wall portion between the transversely central portion of the front edge side of the gas inlet port and the transversely central portion at the upper edge of the passenger""s side wall portion. Moreover, the other gripped portion is located at the transversely central portion of the peripheral wall portion on the back side of the gas inlet port. Moreover, the pulling work is done by pulling those gripped portions in the longitudinal direction away from each other. By this pulling work, the portions of the peripheral wall portion on the left and right sides of the gas inlet port can be individually folded up to form valley creases in the longitudinal direction. Moreover, the portions of the peripheral wall portion near the joint to the upper edge of the passenger""s side wall portion can be folded up to form the valley creases in the transverse direction. Merely by gripping and pulling the predetermined portions of the peripheral wall portion, therefore, the peripheral wall portion can be easily preliminarily folded. As a result, the preliminarily folding work can be made more convenient.
In the passenger""s seat airbag device, still moreover, it is preferred that the valley creases in the peripheral wall portion near the joint to the passenger""s side wall portion upper edge and in the transverse direction are arranged on the front side of the rear edge of the gas inlet port.
With this construction, the gas inlet port can easily confront the upper edge near portion of the passenger""s side wall portion directly. Therefore, the pushing force of the inflating gas to push the upper edge near portion of the passenger""s side wall portion can be enhanced to act directly on the upper edge near portion. As a result, the passenger""s side wall portion can be more easily arranged in the vertical direction.
In the passenger""s seat airbag device, still moreover, it is preferred that the valley creases in the peripheral wall portion near the joint to the passenger""s side wall portion upper edge and in the transverse direction are arranged on the front side of the front edge of the gas inlet port.
With this construction, the portion of the peripheral wall portion to be jointed to the passenger""s side wall portion upper edge is not arranged at the position to confront the gas inlet port. Therefore, the gas inlet port can easily confront the upper edge near portion of the passenger""s side wall portion more directly.
In the passenger""s seat airbag device, still moreover, in the preliminarily folded shape of the airbag,
it is preferred that the vicinity of the substantially intermediate portion on the lower side of the peripheral wall portion between the gas inlet port and the passenger""s side wall portion lower edge is so folded in that it is arranged close to the lower edge side of the passenger""s side wall portion and near the rear end of the peripheral wall portion on the passenger""s side wall portion side.
In the folded-up shape of this construction, the peripheral wall portion is folded up to form a tuck at the peripheral wall portion on the back side of the gas inlet port thereby to extend substantially all the area of the passenger""s side wall portion flatly. Even if the distance from the gas inlet port of the airbag to the passenger""s side wall portion is elongated to make the longitudinal size of the peripheral wall portion on the lower side longer, therefore, the airbag can be easily preliminarily folded by adjusting the length of the tuck.
Here, the case in which the distance from the gas inlet port of the airbag to the passenger""s side wall portion is elongated can be easily coped with by the following folding method. At the portion from the front edge side of the gas inlet port in the peripheral wall portion to the upper edge of the passenger""s side wall portion, more specifically, the folding work may be done by forming the transverse creases to enlarge the longitudinal length of the portions to be folded in. Moreover, the valley creases may be formed in multiplicity.
In the passenger""s seat airbag device, in the preliminarily folded shape of the airbag, it is arbitrary:
that the portion to be arranged at a position to confront the gas inlet port is made of a portion of the peripheral wall portion near the upper edge of the passenger""s side wall portion; and
that the upper edge of the passenger""s side wall portion is arranged on the back side of the rear edge of the gas inlet port.
In connection with the preliminarily folded shape, more specifically, the portion to be arranged at the position to confront the gas inlet port, i.e, the portion of the passenger""s side wall portion near the upper edge side may be either the portion of the passenger""s side wall portion itself or the portion of the peripheral wall portion. If the portion near the upper edge of the passenger""s side wall portion is on the peripheral wall portion as in the aforementioned construction, moreover, the portion of the peripheral wall portion near the upper edge side of the passenger""s side wall portion is forcibly pushed up in advance at the initial stage of the extension/inflation of the airbag. Moreover, the passenger""s side wall portion is arranged at its upper edge side in the vicinity of the portion to confront the gas inlet port. Therefore, the passenger""s side wall portion is also quickly arranged generally in the vertical direction as the portion to confront the gas inlet port is extended (i.e., the portion of the peripheral wall portion near the upper edge side of the passenger""s side wall portion). At this time, the upper edge itself of the passenger""s side wall portion is arranged on the back side of the rear edge of the gas inlet port. Therefore, the passenger""s side wall portion being extended/inflated is arranged generally in the vertical direction while being suppressed in its height. As a result, the passenger""s side wall portion being extended/inflated and arranged generally in the vertical direction is moved to the back side in the height-suppressed state. This behavior of the airbag can protect the passenger properly without applying a partial pushing force to the passenger, when the seated passenger has a small height.